题解 | #【模板】链表#

import java.math.*;
import java.util.*;
import java.lang.*;
import java.io.*;
import java.awt.*;

public class Main {
    static FastReader sc = new FastReader();
    
    static void solve01() {
//         FastReader sc = new FastReader();
        int t = Integer.parseInt(sc.nextLine());
        MyLinkedList ll = new MyLinkedList();
        while (t-- > 0) {
            String arr[] = sc.nextLine().split(" ");
            switch(arr[0]) {
                case "insert":
                    ll.insert(arr[1], arr[2]);
                    break;
                case "delete":
                    ll.delete(arr[1]);
                    break;
            }
//             if (arr[0].equals("insert")) {
//                 ll.insert(arr[1], arr[2]);
//             }
//             else if (arr[0].equals("delete")) {
//                 ll.delete(arr[1]);
//             }
        }
        ll.show();
        
    }
    
    public static void main(String[] args) {
        solve01();
        
    }
    
    
           //输出
    static PrintWriter out;

    //输入类
    static class FastReader {
        BufferedReader br;
        StringTokenizer st;

        public FastReader() {
            br = new BufferedReader(new InputStreamReader(System.in));
            out = new PrintWriter(System.out);
        }

        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }

        long nextLong() {
            return Long.parseLong(next());
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }

        BigInteger nextBigInteger() {return new BigInteger(next());}

        BigDecimal nextBigDecimal() {return new BigDecimal(next());}

        String nextLine() {
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
    }
}

class MyLinkedList {
    private Node head;
    private int length;
    
    public MyLinkedList() {
        head = new Node(null);
        length = 0;
    }
    
    public boolean isEmpty() {
        return length == 0;
    }
    
    public void insert(String x, String y) {
        Node cur = head;
        Node insertNode = new Node(y);
        while (cur.next != null) {
            if (cur.next.data.equals(x)) {
                insertNode.next = cur.next;
                cur.next = insertNode;
                length++;
                return;
                
            }
            cur = cur.next;
        }
        insertNode.next = cur.next;
        cur.next = insertNode;
        length++;
    }
    
    public void delete(String x) {
        Node cur = head;
        while (cur.next != null) {
            if (cur.next.data.equals(x)) {
                cur.next = cur.next.next;
                length--;
                return;
            }
            cur = cur.next;
        }
        
    }
    
    public void show() {
        if (isEmpty()) {
            System.out.println("NULL");
            return;
        }
        Node cur = head.next;
        for (int i = 0; i < length - 1; i++) {
            System.out.print(cur.data + " ");
            cur = cur.next;
        }
        System.out.println(cur.data);
        
    }

}

class Node {
    String data;
    Node next;
    
    public Node() {}
    public Node(String data) { this.data = data; }
}